Bought Ride w a 383 Mopar that had been dormant in a garage for 25 yrs. Went thru the normal wake up procedures and have it running pretty good. New points plugs cap wires carb (holley 650) oil etc... I gotta keep the idle up around 1200 rpm so it doesn't run ruff and stall when putting into gear @ idle. It's got a mild cam so I think S/B OK @ 800-900 rpm but not? Everything checks out w meters for mix, point gap, dwell etc...When waking it up noticed it appeared to be built fresh and put away and barely drove. Steering design was all F'ed up so probably couldn't be driven very far. I did some fab work & got the steering straitened out so it runs fine on the road normal and pushing it w idle at or above 1200 so I don't stall at lites and stops? Short of tearing it down wadda'ya think? Rusty valves from sitting so long was my thought?
Warm engine to operating temp. Remove air cleaner, gain access to choke flap on Holley. Run RPM up to 2500, close choke flap manually as you open throttle, don't kill engine, just choke it 'violently', clear it out at 2,000 RPM, then repeat, 4 or 5 times. If idle is stronger, adjust idle air screws, then put in gear. Idle jets are probably clogged with oxidation from sitting dormant so long. Actually, it is BEST to remove top, remove idle and main jets, tie a 20" piece of cotton string to your vise (or your wife) and put the string thru the jet bores, one at a time...polish the insides of all the jets, re-install them, and reattach the top. Obviously, take care NOT to mix them up! (seen it done, mechanic searched everywhere but there to find the problem!) This was a Factory operation for multiple-carbureter BMW sixes. I attest that it works.
8 degrees advanced, haven't checked vacuum reading. Will do next. probably best out of the large port the pcv is connected to? S/B 20Hg ?
Getting ready to see what vacuum reading is at main port on rear of carb. The dist. has no vacuum to it as is a mechanical advance so thew only port I removed the factory plugs on the Holley was the main in the rear & it's attached to a new hose going to the pcv. rechecked all the other ports again and plugs in place and tight. Pulled carb and gasket show even pressure marks on gasket on top and bottom. I'll report back after vacuum measured.
Does it have power brakes?Cover primary side of carb with fingers see if the idle changes or spray a little carb cleaner while idling into the primary side and see if it smooths out
When you guys are asking for help,please check all the tuneup info,tell us what engine it is,and what problem you are having please. Don't guess.
Not saying this is definitely the problem, but I'll give you another option to explore from an issue I had with my 383. New-to-me used 383, put together out of a used short block and the top end of a good 383 I had. Would start easy, idle smoothly. But put it in gear, and it would pop and spit through the carb, have a difficult time accelerating through the powerband. Vacuum leak was my first thought. Had the intake off the engine 3 times, used loads of RTV, same issues. It wound up being that the outer ring of the balancer had spun slightly on the keyed center, so when I set timing, what I thought was proper timing was 25 degrees retarded. Realizing this, I put a screwdriver in the #1 cylinder, felt for TDC, marked the balancer with a sharpie, reset the timing, and I haven't touched it in 10 years.
No power brakes, fingers over primary side of car tries to stall release comes back quicly, brake fluid into primaries tries to stall comes back after quickly, same problem after.
I'll check it but don't think so. The car runs great thru gears driving normal and accelerating until braking to a stop in gear. Doesn't like to idle at normal idle rpm when putting in gear while braked either. If idle set at under 1200rmp in conditions described it runs rough & stalls if u don't give it gas & bring it back to 1200rpm
i had the same issue with an ot 69 charger 383, vacuum leak, i battled with it a ton, i had an edelbrock on it with an adapter, when i finally rebuilt a correct carb for the manifold i had, i think it was a quadra jet i cant remember but im pretty sure. they had manifolds for every carb pretty much. it fixed all my problems, check alm vac hoses, make sure theyre tight wiyh no tears,check BOTH ENDS.
1969, 383, #'s check out for engine and yr, 85 yr old I bought from said drive train was from a Roadrunner. It has a lope that smooths out @ & 1200rpm. Could it be more than a mild cam & needs rpm that high? 150psi +or - 5, did compression test after cleaning oiling cyinders turning new oil starting & running for a 45 min to an hour. Let cool enough to test.
No brake fluid thru carb please,or did you mean brake clean.What does comp and vacuum show?Try advancing the base timing to highest vacuum reading or to 12 to 14 BTDC
Just because it's "new" doesn't mean it right. If timing is correct, point at the right dwell/electronic are right, sp wiring has right resistance, comp is even and valve lash is correct, I would look to the carb. I personally don't like Holleys on the street but all have the good and bad points.
I have a Edelbrock 1401 no auto choke on my 442, used to run a Holley 750 & always ran good with it. Maybe I'll swap'em out to check it.
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